The present invention relates to a process and an apparatus for reducing the length of the lead-in thread in circular knitting machines, and in particular in double-cylinder circular hosiery-making or knitting machines.
It is known that in double-cylinder circular hosiery-making or knitting machines, at the end of the manufacturing process the thread or threads used to produce the knitted fabric are cut and retained by way of a suitable cutting and clamping device which laterally faces the needle cylinder. At the end of the manufacturing process, the thread accordingly runs from the corresponding thread guide that dispensed it to the cutting and clamping device that retains it after cutting it.
At the beginning of a new manufacturing process the thread guide is actuated so that its thread delivery end moves toward the needle work area and the cutting and clamping device is actuated so as to release the end of the thread which, as a consequence of the suction that is present in the needle cylinders, is drawn into the slot that divides the lower needle cylinder from the upper needle cylinder. The needles are then moved into the active position, at the feed or drop served by the thread guide, so as to engage the dispensed thread and form new loops of knitting.
Due to the fact that the end of the thread is released by the cutting and clamping device and is drawn into the needle cylinders before the thread is taken by the needles to form the loops of knitting, at the end of the knitting of the item said item has a lead-in thread which protrudes at the region that was knitted first.
This lead-in thread, which is not acceptable from an aesthetic point of view, must be cut with a manual operation in a subsequent finishing step which affects the overall production costs of the item.